search for correct include path, when configured for libstdc++-v3

[Matthias Klose]

the INTERFACE definition for libstdc++-v3 moved from Makefile.in to
configure.in

2000-10-16  Matthias Klose  <doko@debian.org> 
 
	* config.if: Search libstdc++-v3/configure.in for INTERFACE,
	  when configured for libstdc++-v3.

--- config.if~	Tue May  2 02:51:59 2000
+++ config.if	Mon Oct 16 01:24:56 2000
@@ -23,15 +23,12 @@
 
 if [ "${enable_libstdcxx_v3}" = "yes" ] ; then
   libstdcxx_srcdir=${if_topsrcdir}/libstdc++-v3
+  # We check libstdc++-v3/configure.in for libstdcxx_interface.
+  libstdcxx_interface=`grep "^INTERFACE" ${libstdcxx_srcdir}/configure.in | sed 's/INTERFACE[ 	]*=[ 	]*\(.*\)/\1/'`
 else
   libstdcxx_srcdir=${if_topsrcdir}/libstdc++
-fi
-
-if [ -f ${libstdcxx_srcdir}/Makefile.in ]; then
-# We check libstdc++ for libstdcxx_interface.
-libstdcxx_interface=`grep "^INTERFACE" ${libstdcxx_srcdir}/Makefile.in | sed 's/INTERFACE[ 	]*=[ 	]*\(.*\)/\1/'`
-else
-libstdcxx_interface=
+  # We check libstdc++/Makefile.in for libstdcxx_interface.
+  libstdcxx_interface=`grep "^INTERFACE" ${libstdcxx_srcdir}/Makefile.in | sed 's/INTERFACE[ 	]*=[ 	]*\(.*\)/\1/'`
 fi
 
 if [ -f ${if_topsrcdir}/gcc/cp/Makefile.in ]; then